The present invention related to a search method for a radio LAN terminal, a search system for a radio LAN terminal using the search method, and a search program for a radio LAN terminal for searching for, in a radio LAN including a personal computer (PC) and plural apparatuses and terminals (hereinafter referred to as “terminals”) such as a projector capable of communicating with the PC by radio, a desired terminal among the plural terminals.
For example, in a node selection system described in JP-A-2004-200830 that is a type of the search system for a radio LAN terminal, all the terminals such as the projector always advertise identifiers such as IP addresses of the terminals one another with radio signals of an identical field intensity using radio LAN apparatuses for identifier advertisement attached to the terminals to allow a search PC for searching for a terminal to search for a nearest terminal. The search PC measures field intensities of radio signals transmitted from the respective terminals and makes connection to the terminal transmitting the radio signal with the highest filed intensity. All the terminals continue to always advertise the identifiers even after the search PC makes connection to the nearest terminal.
In another node selection system (no publicly known document), a search PC is capable of displaying terminals capable of making connection to the PC via a radio LAN in a form of a random list not including information on distances to the terminals.
However, in the node selection system described in JP-A-2004-200830, on the premise that field intensities of radio signals transmitted by the respective terminals are identical, the search PC searches for a nearest terminal according to strength of radio waves always outputted. Thus, the radio LAN apparatuses for identifier advertisement having identical radio power and capable of always transmitting identifiers have to be attached to all the terminals. Usually, the terminals make connection to the radio LAN by having general-purpose radio LAN cards or the like conforming to a radio LAN standard such as IEEE 802.11b (IEEE 802.11 High-Rate Direct Sequence) inserted therein. These radio LAN cards are manufactured by plural manufacturers. There are plural models even if a manufacturer is identical. Thus, it is difficult to set the radio LAN card to always transmit identifiers at an identical field intensity because of fluctuation in manufacturing and a difference of specifications. Consequently, the node selection system requires dedicated apparatuses, that is, the radio LAN apparatuses for identifier advertisement, as components of the terminals. Thus, it is difficult to add terminals having the general-purpose radio LAN cards inserted therein to the node selection system. The node selection system is a closed system poor in compatibility.
All the plural terminals have to always communicate identifiers of the terminals to the search PC by radio to allow the search PC to search for a nearest one terminal. Moreover, even after the search PC makes connection to the nearest one terminal, the remaining terminals always communicate the identifiers of the terminals to the search PC by radio.
As described above, in the node selection system in the past, since all the plural terminals always communicate with the search PC by radio, power consumption is large.
Since the list of the connectable terminals displayed by the search PC is a random list, information concerning which terminal is located nearest to the search PC is not included in the list.
Therefore, since a user has to search a nearest terminal out of the random list by referring to model numbers or the like of the terminals, search efficiency is not high.